The present invention provides a method and system by which a fixed network radio frequency (RF) communication system is made compliant with the standard CEBus protocol, and to an AMR network comprising concentrator nodes and end meters that are able to utilize the CEBus RF physical layer and protocol while co-existing with other CEBus RF devices that are, or might be, deployed in the proximity of the AMR network. Accordingly, the background information provided below relates specifically to CEBus and AMR systems.
Automatic Meter Reading
The reading of electrical energy, water flow and gas usage has historically been accomplished with meter readers that came on-site and manually documented the readings. Over time, this manual methodology has been enhanced with walk by or drive by meter reading systems that utilize radio communications to and from the person or vehicle. Moreover, in the last few years, there has been a concerted effort to accomplish meter reading by installing fixed communication networks that permit data to flow from the meter to a host computer system without human intervention. These systems have typically been proprietary by design and consequently prevent customers from having dual sources of supply and access to other functions available from the RF technology.
Several fixed network communication systems exist in the market that use proprietary architectures, modulation techniques and/or frequency spectra. Companies such as Cellnet Data Systems, San Carlos, Calif., and Itron, Inc., Spokane, Wash., manufacture two such systems. Utilities that purchase these systems do not have the capability to add functionality to the systems unless they purchase the products from the originator of the technology. The result of this is a reluctance of most utilities to employ large scale AMR systems.
CEBUS
The industry standard CEBUS (Consumer Electronics Bus) protocol (EIA IS-60) was adopted by the Electronics Industries Association (EIA). It relates to a local area network that uses multiple media, including power line, radio, twisted pair, coaxial cable, and infrared signaling, and provides reliable communications within a single residence over one or more physical media. Typically, the products using CEBUS equipment (e.g., the ABB Power T&D Company TranstexT system) have attempted to accomplish home automation tasks such as real time pricing and demand side management. CEBUS power line has typically been the media of choice for these applications.
Copending U.S. patent application Ser. No. 08/828,539, filed Mar. 31, 1997, and titled "Communications Module Based Repeater," discloses a reliable, low cost communications module that is configurable for use in a number of modes in accordance with its location in a CEBUS network. The disclosed modes of operation include a source/interface mode in which the module serves as an interface between a host application and the network, a repeater mode in which the module receives and re-transmits message packets originated by another device and intended for a destination device, and a standalone device mode in which the module serves as a destination device for receiving messages from other devices.
Further background information may be found in U.S. Pat. No. 5,696,695, Dec. 9, 1997, titled "System for Rate-Related Control of Electrical Loads." This patent discloses a system that attempts to cover residential applications of a variety of demand side management features. These features may be initiated at a host site and transmitted to a residence or could be accomplished locally. Communications are transmitted to devices in the home using CEBUS power line or RF technology. This system employs the generic CEBUS protocol as specified in the EIA documentation. The disclosed system, therefore, is an example of a system that could be installed at a residence prior to installation of an AMR network that utilizes CEBUS RF in the manner disclosed herein.
Thus, a system could be installed at a residence to handle several loads within the home, shifting power usage to match the pricing structure programmed into the electric meter. The information in the meter can be extracted using CEBUS powerline or RF by a controller in the home that makes decisions based on the metering data and other critical inputs. The present invention particularly addresses the challenge of providing an AMR system using CEBUS RF without preventing the installed residential CEBUS system from working.